Metal studs are now very widely used for interior drywall construction, particularly for apartment and commercial buildings. With the simple cold-rolled configuration of the standard metal stud, in which the cross-section is uniform throughout its length, problems can arise if a heavy axial load is placed on the stud. If, for example, a stud were installed so that its bottom end abutted a concrete floor and its top end touched either another floor or a roof structure which, under heavy load, may deflect downwardly, the resulting longitudinal compressive stress that would arise in the stud could easily cause the stud to buckle laterally at an intermediate location, thus distorting the wall and requiring it to be replaced.
There is thus a need for a metal stud which is configured in such a way that it can yield to absorb such longitudinal forces, without buckling.
A survey of the prior art has yielded the following patents:
U.S. Pat. No. 3,589,089, issued on Jun. 29, 1971, to Kedel; PA1 U.S. Pat. No. 3,436,887, issued on Oct. 18, 1967, to Grossman; PA1 U.S. Pat. No. 3,460,298, issued on Oct. 3, 1967, to Sowinski; PA1 U.S. Pat. No. 3,736,712, issued on Jun. 5, 1973, to Muto; PA1 U.S. Pat. No. 3,831,333, issued on Aug. 27, 1974, to Nelsson; PA1 U.S. Pat. No. 4,712,351, issued on Dec. 15, 1987, to Kasprzak; PA1 U.S. Pat. No. 4,793,113, issued on Dec. 27, 1988, to Bodnar; PA1 U.S. Pat. No. 4,869,040, issued on Sep. 26, 1989, to Howell. PA1 a main wall defined between two parallel side edges, PA1 two lateral walls, each lateral wall having two parallel side edges of which one is contiguous with a side edge of the main wall, and PA1 an accordionated region at a location intermediate the ends of the stud but adjacent to one end thereof, where each of the lateral walls and main wall is formed to define at least one peak configuration fully spanning the respective wall, each such configuration including two flanks oblique to the main stud direction and converging to define an apex, the flanks being delimited by crease lines substantially perpendicular to the main stud direction.
U.S. Pat. No. 4,712,351 is directed to a sliding panel unit made from plastic, wherein one embodiment incorporates a stress-relieving portion including creases or folds 58a (FIG. 4).
U.S. Pat. No. 3,589,089 is also of some interest, in that it illustrates the inclusion of an expansion relief provision, involving various cut-out triangular notches.